failure_case conversion failed : polars.exceptions.ComputeError - pandera(0.19.0b3) with polars about pandera HOT 5 CLOSED

I'm not a pandera user - but this is my understanding of why it is failing:

It seems the failure_case column can be a string or a struct.

In the case of a struct, this fails:

import polars as pl

df = pl.DataFrame({
    'failure_case': [{'case_id': 'abc', 'extract_date': None}]
})

df.with_columns(pl.col("failure_case").cast(pl.String))
# ComputeError: conversion from `struct[2]` to `str` failed in column ...

A struct can be "stringified" in Polars via .struct.json_encode()

>>> df.with_columns(pl.col("failure_case").struct.json_encode())
shape: (1, 1)
┌───────────────────────────────────────┐
│ failure_case                          │
│ ---                                   │
│ str                                   │
╞═══════════════════════════════════════╡
│ {"case_id":"abc","extract_date":null} │
└───────────────────────────────────────┘

But I'm not sure if that's what pandera wants to do in this case.

from pandera.

Good catch! #1608 should address this

from pandera.

Hi @cosmicBboy

I was previously using the 0.19.3b that I installed using
Pip install pre ‘pandera[polars]’

I dnt see the new tag woth your PR.
Can you please let me know how do I use/install the updatws you have made in this PR?

from pandera.

Just cut a new beta release: https://github.com/unionai-oss/pandera/releases/tag/v0.19.0b4

from pandera.

Thanks!

from pandera.